Influence of partial hepatectomy in rats on the activity of hepatic microsomal enzymatic systems

• Published in: European journal of drug metabolism and pharmacokinetics Vol. 22; no. 1; pp. 15 - 23
• Main Authors: MAZA, A. M, GASCON, A. R, CALVO, M. B, HERNANDEZ, R. M, MONTE, M. A, MARIN, J. J. G, DOMINGUEZ-GIL, A, PEDRAZ, J. L
• Format: Journal Article
• Language: English
• Published: Genève Médecine et hygiène 01.01.1997
• Subjects: Aminopyrine N-Demethylase - metabolism; Aniline Hydroxylase - metabolism; Animals; Biological and medical sciences; Cytochrome P-450 Enzyme System - metabolism; Cytochromes b5 - metabolism; Fundamental and applied biological sciences. Psychology; Glutathione - metabolism; Hepatectomy; Liver - chemistry; Liver - growth & development; Liver - surgery; Liver Regeneration - physiology; Liver. Bile. Biliary tracts; Male; Microsomes, Liver - enzymology; NADPH-Ferrihemoprotein Reductase - metabolism; Oxidoreductases, O-Demethylating - metabolism; Rats; Rats, Wistar; Vertebrates: digestive system; Weight Loss; Unspecific monooxygenase; Rat; Enzyme; Cytochrome P450; Rodentia; Microsome; Hepatectomy; Vertebrata; Experimental disease; Mammalia; Cytochrome b; Enzymatic activity; Surgery; Animal; Drug-metabolizing enzyme; Oxidoreductases; Glutathione
• ISSN: 0378-7966; 2107-0180
• DOI: 10.1007/BF03189780

The influence of partial hepatectomy on the activity of the hepatic microsomal enzymatic systems was determined in rats. Cytochrome P-450, cytochrome b5, four mixed functional oxidase (MFO) activities (microsomal aniline hydroxylase, p-nitroanisole O-demethylase, aminopyrine N-demethylase and NADPH cytochrome c reductase) and glutathione levels were measured in unhepatectomized rats (control group) and in hepatectomized rats 12 h, 24 h, 3 days and 6 days after 70% hepatectomy. Following surgery the remaining lobes of the liver grow rapidly in order to restore the original liver mass. Partial hepatectomy significantly reduces cytochrome P-450 and b5 content in the remaining liver as well as the four MFO activities studied. But when the enzymatic systems are expressed as nmoles/mg microsomal protein, only cytochrome P-450 shows statistical differences. The hepatic biotransformation capacity of drugs and xenobiotics decreases during the regeneration period due to the reduction of hepatic mass rather than because of a reduction of their metabolic capacity. Glutathione levels are increased after partial hepatectomy but increased glutathione-dependent protector mechanisms are not expected.